In 1464 while residing in Taranto with his father, he was ordered to lead an escort for Ippolita Maria Sforza, eldest daughter of the Duke of Milan and fiancée of his brother Alphonse, from Milan to Naples. He left Naples on 18 March 1465 with 320 riders and learned while en route on March 30 about the death of his mother. He was received at Rome on April 2, 1465 by Pope Paul II who presented him with the golden rose. He then went to Siena and Florence, where he was received on April 17 by Lorenzo the Magnificent. He then journeyed to Milan, and stayed until June 7, ordered by the bride to return to Naples. He followed the same route when he was stopped by the Duke of Milan, who threatened to break up the wedding in Siena until diplomacy was opened up. He returned to Naples on 14 September.[3]

Naples in the fifteenth century. La Tavola Strozzi probably represents the triumphal entry of the fleet of Ferdinand I after the Battle of Ischia in 1465

From 1464 to 1473, he served as a lieutenant of the King of Naples in Capitanata, Terre de Bari and Terre d'Otrante, his roles receiving liege homage, overseeing the collection of taxes and enforcing trade agreements with the Republic of Venice. He also participated in the diplomatic activity that his father led, especially in receiving the lords the King of Naples wished to enter into an alliance with. He welcomed in March 1472 in Aversa and Naples, Jean della Rovere, prefect of Rome, lord of Senigallia and nephew of Pope Sixtus IV (della Rovere François), and on August 30, 1473 received Charles Manfredi, lord of Faenza.[3]

As early as April 1470, Charles the Bold proposed to marry his daughter and sole heiress Mary to Frederick, and the plans took shape in November 1471, after the signing of an alliance between the Duke of Burgundy and the King of Naples.[4]

In February 1472, King Ferdinand received Frederick with the aim to aid in the project, a Burgundian delegation insisted that Charles the Bold, for its part, had not stopped his choice. Frederick’s sister Eleanor expressed confidence in the idea that the Duke of Burgundy sought to join in alliance before Easter. But these hopes were shattered during the summer when they learned, at the court of Naples, of the engagement of Mary of Naples to Nicholas of Lorraine, a claimant to the Kingdoms of Naples and Aragon, resulting from the alliance concluded between the dukes of Burgundy and Lorraine, and Charles the Bold initialled by Arras on May 25, 1472, and signed by Nicholas, in turn, on May 27, 1472. Mary gave her consent to the promise of marriage on June 13, 1472 and Nicolas sent her his "Mons-en-Hainaut" the same day.[5]

In October 1472, a new Burgundian embassy arrived at Naples reassuring about the arrangement of Mary of Burgundy and the relationship between Charles the Bold and the King of Naples. On leaving, they left behind two squires responsible for teaching Frederick better French. Charles the Bold used the eventual marriage of his daughter as an instrument of his diplomacy.[3]

The engagement of Mary and Nicholas never came to fruition. On November 5, 1472, at the camp of Charles the Bold in Beaurevoir, Nicholas waived his promise of marriage without jeopardizing the alliance between the two dukes. Mary renounced her betrothal on 3 December.[5]

In 1473, due to both sides failing to meet the commitments of the alliance, along with the rumor of Charles's reckless plan to marry his daughter to Maximilian, the son of Emperor Frederick III, King Ferdinand began exploring the possibility of a union between Frederick and Joanna, daughter of John II of Aragon. He also raised the possibility of a marriage with a daughter of Luca Sanseverino, Prince of Bisignano, before returning to his original wedding arrangements.[5]

King Ferdinand decided to promote the possibility of marriage between Frederick and the daughter of Charles the Bold and sought any opportunity that would require the Duke of Burgundy to accept the offer. On November 26, 1474 in Foggia, Ferdinand gave Francesco Bertini, Bishop of Capaccio, as ambassador to the court of Burgundy, full powers to conduct the negotiations. On November 28, Alphonse, Duke of Calabria, was confirmed as an ambassador for the negotiations by his father and his brother the bishop of Capaccio.[3]

Frederick left Naples on October 26, 1474, with a princely retinue and many visits in Italy, awaited the opportunity to go to Dijon. He was received in Rome, Urbino, and Ferrara with his brother-in-law Ercole d' Este. On January 5, 1475, accompanied by 400 members of his retinue, he was welcomed by the Doge of Venice Pietro Mocenigo in an elaborate reception, during which the delegations of the Serenissima Republic were welcomed at Bucentaure.[3]

The opportunity to join the court of Charles the Bold was furnished by the signing of a military agreement between Charles and Galeazzo Maria Sforza on 30 January. In early February, he left Milan for Turin where Yolande de France, who was the major broker of the alliance between the Dukes of Burgundy and Milan, entrusted him as the master of arms and archery. He was stationed at Besançon at the end of February, when Charles the Bold besieged Neuss.

News spread quickly among the Italian courts, and Guy de Brimeu, counselor of the Duke of Burgundy, was particularly surprised about the developing news of the marriage. Ferdinand knew that the wedding plans were fluctuating and subject to political uncertainties and questions, and this was even more true elsewhere like in the Court of Burgundy. He confided in his son with two major tasks: the first was to give to Charles the Bold the collar of the Order of the Ermine he had created, and welcome him to the Order of the Knights of the Fleece or, the second was to replace, in the entourage of Charles, Nicola di Monforte Pietravalle, Count of Campobasso,[3] a former vassal of Ferdinand who served René of Anjou and had ties to John of Calabria, who recruited mercenaries in Piedmont, Lombardy and Emilia to serve in the army of Burgundy.[6]

While Frederick of Aragon arrived at the court of Burgundy, Antoine de Bourgogne, the half- brother of Charles the Bold, set off to Naples with his son Philippe, François d'Este, an illegitimate son of Lionel Este and Guillaume de Rochefort and a hundred men to submit to King Ferdinand the collar of the Order of the Golden Fleece in which he was admitted to the Chapter of Valenciennes in 1473 at the request of Charles the Bold. Arriving at Mechelen around 15 February, Antoine de Bourgogne stayed at Moncalieri from March 4 to March 6 at the Duchess Yolande’s estate. He likely met with Frederick at this time at the estate of Chambéry.[7]

Antoine de Bourgogne was received at the Milanese court from 9 March to 16 March 1475, then traveled to Naples where he was welcomed by the Duke of Calabria Alphonse on April 15. On April 20 King Ferdinand was ordained in the Order of the Golden Fleece, and had sworn to abide by its statutes. The arrival of the Burgundian embassy became an occasion for great festivities including jousts.

He succeeded his nephew as king and soon was forced to fight the claims of Louis XI 's successor, King Charles VIII of France to his kingdom. He was crowned on June 26, 1497. Louis XII of France, took these claims on his own and began the conquest of the kingdom from 1499 to 1501 . Frederick had to call upon his cousin Ferdinand II, King of Aragon to repel the French, but the latter, after defeating Louis XII, retained the kingdom for himself. Stripped of his dominions, Frederick was forced to implore the generosity of the King of France, who had made him an annuity of thirty thousand pounds on the duchy of Anjou.

The representatives of Louis XII of France and those of Ferdinand and Isabella of Spain signed a secret treaty in Granada on November 11, 1500. The French and Aragonese sovereigns agreed to attack the Kingdom of Naples, conquer it and immediately divide it between themselves. Louis XII would receive Naples, Terra di Lavoro and Abruzzo and the titles of King of Jerusalem and King of Naples; Ferdinand of Aragon would become Duke of Apulia and Duke of Calabria. Each of the two sovereigns sought the endorsement of Pope Alexander VI, the overlord of these hypothetical territories.

In Malaga Ferdinand armed a fleet of 50 vessels carrying 1,200 horses and 8,000 infantry under the command of Gonzalo de Córdoba. These forces sailed to support the Venetians in the battles against the Turks, then returned after the campaign around 1500-1501 to Sicily. French and Aragonese forces occupied Naples in 1501.

This article is missing information about the last three years of Frederick's life, and details of his death and burial.. Please expand the article to include this information. Further details may exist on the talk page.(March 2016)

^C. Warr and J. Elliott (2008), "Introduction: Reassessing Naples, 1266–1713", Art History, 31: 423–37. He was the fourth Frederick to call himself King of Sicily, ruling under the title Federicus Dei gratia rex Siciliae ("Frederick by the grace of God king of Sicily"); the second Frederick to rule peninsular southern Italy after the Emperor Frederick II and thus sometimes called "Frederick II of Naples"; and the first Frederick to actually rule over the so-called Kingdom of Naples.

^first cousins once removed, since Frederick was son of Ferdinand I, son of Alfonso V and Ferdinand II was son of John II, brother of Ferdinand I.